A hydrogenated ring-opening polymer of a norbornene-based monomer is one type of cycloolefin polymer that exhibits excellent transparency, low birefringence, excellent moldability, and the like, and has been used as a material that can be applied to various applications such as optical applications.
A hydrogenated ring-opening polymer of a norbornene-based monomer is normally obtained as an amorphous polymer having an atactic structure. However, a hydrogenated ring-opening polymer of a norbornene-based monomer that has an atactic structure may exhibit insufficient solvent resistance and the like depending on the application. In order to improve the performance of a hydrogenated ring-opening polymer of a norbornene-based monomer, it has been proposed to provide a hydrogenated ring-opening polymer of a norbornene-based monomer with solvent resistance by producing a hydrogenated ring-opening polymer of a norbornene-based monomer that has tactic structure.
For example, Patent Document 1 discloses that a hydrogenated amorphous norbornene-based ring-opening polymer is provided with solvent crack resistance by mixing a hydrogenated crystalline dicyclopentadiene ring-opening polymer with a hydrogenated amorphous norbornene-based ring-opening polymer. Patent Document 2 discloses that a copolymer that includes a hydrogenated crystalline dicyclopentadiene ring-opening polymer segment and a hydrogenated amorphous norbornene-based ring-opening polymer segment exhibits solvent crack resistance.